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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_config.cstdint"></a><a class="link" href="cstdint.html" title="Standard Integer Types">Standard Integer Types</a>
</h2></div></div></div>
<div class="toc"><dl class="toc">
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.overview">Overview</a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.rationale">Rationale</a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.ce"><span class="emphasis"><em>Caveat emptor</em></span></a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.exact_width_integer_types">Exact-width
      integer types</a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.minimum_width_integer_types">Minimum-width
      integer types</a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.fastest_minimum_width_integer_types">Fastest
      minimum-width integer types</a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.greatest_width_integer_types">Greatest-width
      integer types</a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.integer_constant_macros">Integer
      Constant Macros</a></span></dt>
<dt><span class="section"><a href="cstdint.html#boost_config.cstdint.intptr">Integers for Storing Pointers</a></span></dt>
</dl></div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.overview"></a><a class="link" href="cstdint.html#boost_config.cstdint.overview" title="Overview">Overview</a>
</h3></div></div></div>
<p>
        The header <code class="literal"><a href="../../../../../boost/cstdint.hpp" target="_top">&lt;boost/cstdint.hpp&gt;</a></code>
        provides the typedef's useful for writing portable code that requires certain
        integer widths. All typedef's are in namespace boost.
      </p>
<p>
        The specifications for these types are based on the ISO/IEC 9899:1999 C Language
        standard header &lt;stdint.h&gt;. The 64-bit types required by the C standard
        are <span class="emphasis"><em>not required</em></span> in the boost header, and may not be
        supplied for all platforms/compilers, because <code class="literal">long long</code>
        is not [yet] included in the C++ standard.
      </p>
<p>
        See <a href="../../../test/cstdint_test.cpp" target="_top">cstdint_test.cpp</a> for
        a test program.
      </p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.rationale"></a><a class="link" href="cstdint.html#boost_config.cstdint.rationale" title="Rationale">Rationale</a>
</h3></div></div></div>
<p>
        The organization of the Boost.Integer headers and classes is designed to
        take advantage of &lt;stdint.h&gt; types from the 1999 C standard without
        causing undefined behavior in terms of the 1998 C++ standard. The header
        &lt;boost/cstdint.hpp&gt; makes the standard integer types safely available
        in namespace <code class="literal">boost</code> without placing any names in namespace
        <code class="literal">std</code>. The intension is to complement rather than compete
        with the C++ Standard Library. Should some future C++ standard include &lt;stdint.h&gt;
        and &lt;cstdint&gt;, then &lt;boost/cstdint.hpp&gt; will continue to function,
        but will become redundant and may be safely deprecated.
      </p>
<p>
        Because these are boost headers, their names conform to boost header naming
        conventions rather than C++ Standard Library header naming conventions.
      </p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.ce"></a><a class="link" href="cstdint.html#boost_config.cstdint.ce" title="Caveat emptor"><span class="emphasis"><em>Caveat emptor</em></span></a>
</h3></div></div></div>
<p>
        As an implementation artifact, certain C &lt;limits.h&gt; macro names may
        possibly be visible to users of &lt;boost/cstdint.hpp&gt;. Don't use these
        macros; they are not part of any Boost-specified interface. Use <code class="literal">boost::integer_traits&lt;&gt;</code>
        or <code class="literal">std::numeric_limits&lt;&gt;</code> instead.
      </p>
<p>
        As another implementation artifact, certain C &lt;stdint.h&gt; typedef names
        may possibly be visible in the global namespace to users of &lt;boost/cstdint.hpp&gt;.
        Don't use these names, they are not part of any Boost-specified interface.
        Use the respective names in namespace <code class="literal">boost</code> instead.
      </p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.exact_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.exact_width_integer_types" title="Exact-width integer types">Exact-width
      integer types</a>
</h3></div></div></div>
<p>
        The typedef <code class="literal">int#_t</code>, with # replaced by the width, designates
        a signed integer type of exactly # bits; for example <code class="literal">int8_t</code>
        denotes an 8-bit signed integer type. Similarly, the typedef <code class="literal">uint#_t</code>
        designates an unsigned integer type of exactly # bits.
      </p>
<p>
        These types are optional. However, if a platform supports integer types with
        widths of 8, 16, 32, 64, or any combination thereof, then &lt;boost/cstdint.hpp&gt;
        does provide the corresponding typedefs.
      </p>
<p>
        The absence of int64_t and uint64_t is indicated by the macro <code class="computeroutput"><span class="identifier">BOOST_NO_INT64_T</span></code>.
      </p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.minimum_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.minimum_width_integer_types" title="Minimum-width integer types">Minimum-width
      integer types</a>
</h3></div></div></div>
<p>
        The typedef <code class="literal">int_least#_t</code>, with # replaced by the width,
        designates a signed integer type with a width of at least # bits, such that
        no signed integer type with lesser size has at least the specified width.
        Thus, <code class="literal">int_least32_t</code> denotes the smallest signed integer
        type with a width of at least 32 bits. Similarly, the typedef name <code class="literal">uint_least#_t</code>
        designates an unsigned integer type with a width of at least # bits, such
        that no unsigned integer type with lesser size has at least the specified
        width.
      </p>
<p>
        The following minimum-width integer types are provided for all platforms:
      </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
            <code class="literal">int_least8_t</code>
          </li>
<li class="listitem">
            <code class="literal">int_least16_t</code>
          </li>
<li class="listitem">
            <code class="literal">int_least32_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_least8_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_least16_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_least32_t</code>
          </li>
</ul></div>
<p>
        The following types are available only if, after including &lt;boost/cstdint.hpp&gt;,
        the macro BOOST_NO_INT64_T is not defined:
      </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
            <code class="literal">int_least64_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_least64_t</code>
          </li>
</ul></div>
<p>
        All other minimum-width integer types are optional.
      </p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.fastest_minimum_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.fastest_minimum_width_integer_types" title="Fastest minimum-width integer types">Fastest
      minimum-width integer types</a>
</h3></div></div></div>
<p>
        The typedef <code class="literal">int_fast#_t</code>, with # replaced by the width,
        designates the fastest signed integer type with a width of at least # bits.
        Similarly, the typedef name <code class="literal">uint_fast#_t</code> designates the
        fastest unsigned integer type with a width of at least # bits.
      </p>
<p>
        There is no guarantee that these types are fastest for all purposes. In any
        case, however, they satisfy the signedness and width requirements.
      </p>
<p>
        The following fastest minimum-width integer types are provided for all platforms:
      </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
            <code class="literal">int_fast8_t</code>
          </li>
<li class="listitem">
            <code class="literal">int_fast16_t</code>
          </li>
<li class="listitem">
            <code class="literal">int_fast32_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_fast8_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_fast16_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_fast32_t</code>
          </li>
</ul></div>
<p>
        The following types are available only if, after including &lt;boost/cstdint.hpp&gt;,
        the macro BOOST_NO_INT64_T is not defined:
      </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
            <code class="literal">int_fast64_t</code>
          </li>
<li class="listitem">
            <code class="literal">uint_fast64_t</code>
          </li>
</ul></div>
<p>
        All other fastest minimum-width integer types are optional.
      </p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.greatest_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.greatest_width_integer_types" title="Greatest-width integer types">Greatest-width
      integer types</a>
</h3></div></div></div>
<p>
        The typedef <code class="literal">intmax_t </code>designates a signed integer type
        capable of representing any value of any signed integer type.
      </p>
<p>
        The typedef <code class="literal">uintmax_t</code> designates an unsigned integer type
        capable of representing any value of any unsigned integer type.
      </p>
<p>
        These types are provided for all platforms.
      </p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.integer_constant_macros"></a><a class="link" href="cstdint.html#boost_config.cstdint.integer_constant_macros" title="Integer Constant Macros">Integer
      Constant Macros</a>
</h3></div></div></div>
<p>
        The following macros are always defined after inclusion of this header, these
        allow integer constants of at least the specified width to be declared: INT8_C,
        UINT8_C, INT16_C, UINT16_C, INT32_C, UINT32_C, INTMAX_C, UINTMAX_C.
      </p>
<p>
        The macros INT64_C and UINT64_C are also defined if the the macro BOOST_NO_INT64_T
        is not defined.
      </p>
<p>
        The C99 macro __STDC_CONSTANT_MACROS is also defined as an artifact of the
        implementation.
      </p>
<p>
        For example:
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">cstdint</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>

<span class="comment">// Here the constant 0x1FFFFFFFF has the correct suffix applied:</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">uint64_t</span> <span class="identifier">c</span> <span class="special">=</span> <span class="identifier">INT64_C</span><span class="special">(</span><span class="number">0</span><span class="identifier">x1FFFFFFFF</span><span class="special">);</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_config.cstdint.intptr"></a><a class="link" href="cstdint.html#boost_config.cstdint.intptr" title="Integers for Storing Pointers">Integers for Storing Pointers</a>
</h3></div></div></div>
<p>
        The typedefs <code class="literal">intptr_t</code> and <code class="literal">uintptr_t</code>
        defined signed and unsigned integers respectively each capable of storing
        a pointer. The macro <code class="literal">BOOST_HAS_INTPTR_T</code> is set when these
        types are available.
      </p>
</div>
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<td align="right"><div class="copyright-footer">Copyright © 2001-2007 Beman Dawes, Vesa Karvonen, John
      Maddock<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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